1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/transfer/push_proxy.c	Sat Feb 20 21:18:28 2010 -0800
     1.3 @@ -0,0 +1,292 @@
     1.4 +/*
     1.5 + * $Id: push_proxy.c,v 1.2 2004/06/02 07:13:02 hipnod Exp $
     1.6 + *
     1.7 + * Copyright (C) 2004 giFT project (gift.sourceforge.net)
     1.8 + *
     1.9 + * This program is free software; you can redistribute it and/or modify it
    1.10 + * under the terms of the GNU General Public License as published by the
    1.11 + * Free Software Foundation; either version 2, or (at your option) any
    1.12 + * later version.
    1.13 + *
    1.14 + * This program is distributed in the hope that it will be useful, but
    1.15 + * WITHOUT ANY WARRANTY; without even the implied warranty of
    1.16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    1.17 + * General Public License for more details.
    1.18 + */
    1.19 +
    1.20 +#include "gt_gnutella.h"
    1.21 +
    1.22 +#include "gt_node.h"
    1.23 +#include "gt_packet.h"     /* htovs() */
    1.24 +
    1.25 +#include "transfer/push_proxy.h"
    1.26 +
    1.27 +/*****************************************************************************/
    1.28 +
    1.29 +/*
    1.30 + * All this GGEP stuff will move somewhere else soon.  Just haven't decided
    1.31 + * where to put it.
    1.32 + */
    1.33 +
    1.34 +/*****************************************************************************/
    1.35 +
    1.36 +#define PROXY_DEBUG          gt_config_get_int("push_proxy/debug=0")
    1.37 +
    1.38 +/*****************************************************************************/
    1.39 +
    1.40 +#define GGEP_HDR_LEN         (1)    /* 0xc3 */
    1.41 +#define GGEP_EXT_MAX_LEN     (63)   /* use only a single len chunk for now */
    1.42 +
    1.43 +enum ggep_length_flags
    1.44 +{
    1.45 +	GGEP_LEN_NOT_LAST      = 0x80,  /* not the last chunk */
    1.46 +	GGEP_LEN_LAST          = 0x40,  /* last length chunk flag */
    1.47 +};
    1.48 +
    1.49 +enum ggep_extension_flags
    1.50 +{
    1.51 +	GGEP_EXTF_LAST         = 0x80,  /* last extension */
    1.52 +	GGEP_EXTF_COBS_ENCODED = 0x40,  /* encoded with COBS-encoding */
    1.53 +	GGEP_EXTF_COMPRESSED   = 0x20,  /* compressed */
    1.54 +	GGEP_EXTF_RESERVED     = 0x10,  /* reserved */
    1.55 +
    1.56 +	/* lower 4 bits is identifier length */
    1.57 +};
    1.58 +
    1.59 +/*****************************************************************************/
    1.60 +
    1.61 +struct proxy_addr
    1.62 +{
    1.63 +	in_addr_t  ipv4;
    1.64 +	in_port_t  port;
    1.65 +};
    1.66 +
    1.67 +typedef struct ggep
    1.68 +{
    1.69 +	uint8_t   *block;
    1.70 +	size_t     block_len;
    1.71 +	size_t     offset;
    1.72 +	size_t     last_ext_offset;
    1.73 +	BOOL       error;
    1.74 +} ggep_t;
    1.75 +
    1.76 +/*****************************************************************************/
    1.77 +
    1.78 +static ggep_t     proxy_block;
    1.79 +static Dataset   *proxies;
    1.80 +
    1.81 +/*****************************************************************************/
    1.82 +
    1.83 +static BOOL ggep_grow (ggep_t *ggep, size_t sz)
    1.84 +{
    1.85 +	uint8_t *new_block;
    1.86 +	size_t   new_size;
    1.87 +
    1.88 +	new_size = ggep->block_len + sz;
    1.89 +	if (!(new_block = realloc (ggep->block, new_size)))
    1.90 +		return FALSE;
    1.91 +
    1.92 +	ggep->block     = new_block;
    1.93 +	ggep->block_len = new_size;
    1.94 +
    1.95 +	return TRUE;
    1.96 +}
    1.97 +
    1.98 +static BOOL ggep_init (ggep_t *ggep)
    1.99 +{
   1.100 +	ggep->block_len       = 1;
   1.101 +	ggep->offset          = 1;
   1.102 +	ggep->last_ext_offset = 0;
   1.103 +	ggep->error           = FALSE;
   1.104 +
   1.105 +	if (!(ggep->block = malloc (1)))
   1.106 +		return FALSE;
   1.107 +
   1.108 +	/* append magic byte */
   1.109 +	ggep->block[0] = 0xc3;
   1.110 +
   1.111 +	return TRUE;
   1.112 +}
   1.113 +
   1.114 +static void ggep_append (ggep_t *ggep, const void *data, size_t data_size)
   1.115 +{
   1.116 +	if (ggep_grow (ggep, data_size) == FALSE)
   1.117 +	{
   1.118 +		ggep->error = TRUE;
   1.119 +		return;
   1.120 +	}
   1.121 +
   1.122 +	assert (ggep->offset + data_size <= ggep->block_len);
   1.123 +	memcpy (&ggep->block[ggep->offset], data, data_size);
   1.124 +	ggep->offset += data_size;
   1.125 +}
   1.126 +
   1.127 +/* TODO: this should use a writev()-like interface */
   1.128 +static BOOL ggep_append_extension (ggep_t *ggep, const char *id,
   1.129 +                                   const uint8_t *data, size_t data_len)
   1.130 +{
   1.131 +	uint8_t id_len;
   1.132 +	uint8_t ext_flags;
   1.133 +	uint8_t ext_data_len;
   1.134 +
   1.135 +	id_len = strlen (id) & 0x0f;
   1.136 +
   1.137 +	/* disable Encoding, Compression, LastExtension bits, len in low 4 bits */
   1.138 +	ext_flags = id_len;
   1.139 +
   1.140 +	/* track position of last extension for setting LastExtension bit */
   1.141 +	ggep->last_ext_offset = ggep->offset;
   1.142 +
   1.143 +	/* extension flag header */
   1.144 +	ggep_append (ggep, &ext_flags, 1);
   1.145 +
   1.146 +	/* extension identifier */
   1.147 +	ggep_append (ggep, id, id_len);
   1.148 +
   1.149 +	assert (data_len <= GGEP_EXT_MAX_LEN);
   1.150 +	ext_data_len = data_len | GGEP_LEN_LAST; /* add last length chunk flag */
   1.151 +
   1.152 +	/* the extension length */
   1.153 +	ggep_append (ggep, &ext_data_len, 1);
   1.154 +
   1.155 +	/* the extension data */
   1.156 +	ggep_append (ggep, data, data_len);
   1.157 +
   1.158 +	if (ggep->error)
   1.159 +		return FALSE;
   1.160 +
   1.161 +	return TRUE;
   1.162 +}
   1.163 +
   1.164 +static BOOL ggep_seal (ggep_t *ggep)
   1.165 +{
   1.166 +	if (ggep->last_ext_offset == 0)
   1.167 +		return FALSE;
   1.168 +
   1.169 +	/* set the LastExtension bit on the last extension */
   1.170 +	ggep->block[ggep->last_ext_offset] |= GGEP_EXTF_LAST;
   1.171 +	return TRUE;
   1.172 +}
   1.173 +
   1.174 +static void ggep_finish (ggep_t *ggep)
   1.175 +{
   1.176 +	free (ggep->block);
   1.177 +}
   1.178 +
   1.179 +/*****************************************************************************/
   1.180 +
   1.181 +static void ds_add_proxy (ds_data_t *key, ds_data_t *value, void **cmp)
   1.182 +{
   1.183 +	uint8_t           *push_ext     = cmp[0];
   1.184 +	size_t            *push_ext_len = cmp[1];
   1.185 +	in_port_t          port;
   1.186 +	struct proxy_addr *proxy = value->data;
   1.187 +
   1.188 +	port = htovs (proxy->port);
   1.189 +
   1.190 +	if (*push_ext_len + 6 >= GGEP_EXT_MAX_LEN)
   1.191 +		return;
   1.192 +
   1.193 +	/* build the PUSH extension */
   1.194 +	memcpy (&push_ext[*push_ext_len], &proxy->ipv4, 4); *push_ext_len += 4;
   1.195 +	memcpy (&push_ext[*push_ext_len], &port, 2);        *push_ext_len += 2;
   1.196 +}
   1.197 +
   1.198 +static void update_block (ggep_t *ggep)
   1.199 +{
   1.200 +	uint8_t push_ext[GGEP_EXT_MAX_LEN]; /* ugh */
   1.201 +	size_t  push_ext_len;               /* double ugh */
   1.202 +	void   *cmp[2];
   1.203 +
   1.204 +	ggep_finish (ggep);
   1.205 +
   1.206 +	if (ggep_init (ggep) == FALSE)
   1.207 +		return;
   1.208 +
   1.209 +	cmp[0] = push_ext;
   1.210 +	cmp[1] = &push_ext_len;
   1.211 +
   1.212 +	push_ext_len = 0;
   1.213 +	dataset_foreach (proxies, DS_FOREACH(ds_add_proxy), cmp);
   1.214 +	assert (push_ext_len <= GGEP_EXT_MAX_LEN);
   1.215 +
   1.216 +	if (ggep_append_extension (ggep, "PUSH", push_ext, push_ext_len) == FALSE)
   1.217 +		return;
   1.218 +
   1.219 +	ggep_seal (ggep);
   1.220 +}
   1.221 +
   1.222 +/*****************************************************************************/
   1.223 +
   1.224 +static void push_proxy_change (GtNode *node, in_addr_t ipv4,
   1.225 +                               in_port_t port, BOOL add)
   1.226 +{
   1.227 +	struct proxy_addr  addr;
   1.228 +	struct proxy_addr *stored;
   1.229 +
   1.230 +	addr.ipv4 = ipv4;
   1.231 +	addr.port = port;
   1.232 +
   1.233 +	stored = dataset_lookup (proxies, &node, sizeof(node));
   1.234 +	if (PROXY_DEBUG)
   1.235 +	{
   1.236 +		if (add && !stored)
   1.237 +			GT->DBGFN (GT, "adding push proxy %s:%hu", net_ip_str (ipv4), port);
   1.238 +		else if (!add && stored)
   1.239 +			GT->DBGFN (GT, "rming push proxy %s:%hu", net_ip_str (ipv4), port);
   1.240 +	}
   1.241 +
   1.242 +	if (add)
   1.243 +		dataset_insert (&proxies, &node, sizeof(node), &addr, sizeof(addr));
   1.244 +	else
   1.245 +		dataset_remove (proxies, &node, sizeof(node));
   1.246 +
   1.247 +	update_block (&proxy_block);
   1.248 +}
   1.249 +
   1.250 +void gt_push_proxy_add (GtNode *node, in_addr_t ipv4, in_port_t port)
   1.251 +{
   1.252 +	assert (node->push_proxy_ip == 0);
   1.253 +	assert (node->push_proxy_port == 0);
   1.254 +
   1.255 +	push_proxy_change (node, ipv4, port, TRUE);
   1.256 +	node->push_proxy_ip   = ipv4;
   1.257 +	node->push_proxy_port = port;
   1.258 +}
   1.259 +
   1.260 +/*
   1.261 + * This must be called if the port changes, or if the proxy disconnects.
   1.262 + */
   1.263 +void gt_push_proxy_del (GtNode *node)
   1.264 +{
   1.265 +	push_proxy_change (node, node->push_proxy_ip,
   1.266 +	                   node->push_proxy_port, FALSE);
   1.267 +	node->push_proxy_ip   = 0;
   1.268 +	node->push_proxy_port = 0;
   1.269 +}
   1.270 +
   1.271 +BOOL gt_push_proxy_get_ggep_block (uint8_t **block, size_t *block_len)
   1.272 +{
   1.273 +	if (dataset_length (proxies) == 0)
   1.274 +		return FALSE;
   1.275 +
   1.276 +	*block     = proxy_block.block;
   1.277 +	*block_len = proxy_block.block_len;
   1.278 +
   1.279 +	return TRUE;
   1.280 +}
   1.281 +
   1.282 +/*****************************************************************************/
   1.283 +
   1.284 +void gt_push_proxy_init (void)
   1.285 +{
   1.286 +	ggep_init (&proxy_block);
   1.287 +}
   1.288 +
   1.289 +void gt_push_proxy_cleanup (void)
   1.290 +{
   1.291 +	dataset_clear (proxies);
   1.292 +	proxies = NULL;
   1.293 +
   1.294 +	ggep_finish (&proxy_block);
   1.295 +}